Divergent Asymmetric Synthesis of Polycyclic Spiroindolines via Cascade Cycloadditions

Comprehensive Summary The asymmetric construction of polycyclic spiroindolines featuring one or more quaternary stereocenters remains a significant challenge in synthetic chemistry. We report a highly chemoselective and stereoselective cascade cycloadditions of newly designed oxazepino indolones with 5‐methylene‐1,3‐dioxanones, employing an iridium catalyst in combination with the Carreira ligand for the divergent synthesis of chiral polycyclic spiroindolines. This strategy enables the construction of a series of pentacyclic spiroindolines featuring two chiral quaternary stereocenters and one tertiary stereocenter in good yields with excellent chemoselectivity and stereocontrol (30 examples, up to 81% yield, >20 : 1 dr, 99% ee ). The process was scalable, and synthetic transformations of the products were performed to demonstrate their practical utility.